6 February 2020
Vixar launches multi-junction VCSEL technology for 3D sensing
At Photonics West 2020 in San Francisco (4-6 February), Vixar Inc of Plymouth, MN, USA (a subsidiary of Osram GmbH of Munich, Germany) has launched its multi-junction vertical-cavity surface-emitting laser (VCSEL) technology, with a power conversion efficiency of 60% at 940nm. Following its acquisition of Vixar in 2018, Osram has demonstrated dual- and triple-junction VCSELs that provide lower current, increased efficiency and higher speed.
Graphic: Device structure of Vixar’s new multi-junction VCSEL.
The VCSEL market continues to grow rapidly due to benefits including outstanding beam quality, simple design and compact size, says Osram. VCSELs power consumer applications such as 3D cameras and facial recognition in mobile devices, as well as industrial applications like short-range light detection & ranging (LiDAR), machine vision and robotics. There is also potential for use in automotive applications such as in-cabin sensing.
As the next development in VCSELs, the new multi-junction technology can be applied to products in the company’s portfolio, with slope efficiencies of 2W/A in dual junction and 3W/A in triple junction. The power conversion efficiency is a record 60% — significantly higher than the comparable single-junction’s 53% peak wall-plug efficiency.
Osram says that the multi-junction VCSEL offers many significant benefits. For example, greater efficiency reduces the overall thermal load. Higher power density leads to a dramatically reduced chip and package size, enabling simpler optic designs and system architecture.
The higher slope efficiency means that a much lower pulsing forward current is required to reach the same optical power as a single-junction VCSEL. The advantage is greatly reducing the current required, which improves the switching speed of the driver. This reduction of current allows the VCSEL to deliver a 1ns pulse for tens or even hundreds of watts.